An industrial robot is an electro-mechanical machine that is controlled by a computer program, electronic circuits, or both. The industrial robot may be either stationary or mobile (e.g., capable of navigating from one location to another location). For example, the industrial robot may have wheels (or another form of conveyance) to enable the industrial robot to navigate to different locations. Industrial robots that can navigate independently of each other may be referred to as unmanned drive units. An industrial robot may be capable of performing activities using one or more arm-like mechanisms to grasp an item, release the item, etc. Based on the type of task that is to be performed, two or more robots may coordinate their respective activities to perform a task.
Humans may at times enter the areas in which industrial robots are operating. Similarly, an unmanned drive unit may enter an area in which a person is working. When a person and a robotic unit operate in proximity to each other, the person may be inadvertently struck and injured by movement of the robotic unit. Accordingly, it is desirable to implement safety systems to inhibit the movement of industrial robots when a person is nearby.